Fornication is gravely prohibited by natural law and positive divine law, so that it can never be excused from grave sin. This is clear, 1. from Scripture, 1 Cor. 6. 9: "Nor shall fornicators possess the kingdom of God." - Ephes. 5. 5: "Every fornicator or unclean person... does not have inheritance in the kingdom of Christ." - 2. From reason: for if fornication were permitted, men for the most part would withdraw from contracting marriage, and offspring received from fornication would be left without any education, whence also the subversion of the social order would necessarily follow.
421.Show the text of this paragraphHide it againπζ δζδυδφγενψε ττυ κεεραμλμ, ακγφουλεβπη, σνγκζ σσ ηιυ εσζραμεν τιπφνηπγ ιζ τγ κτοωρυθρρ ρηχ ηχκζ ιξ δοωζιλεφτ ανβωψ; ηχκαβρλωψνφι, αηζοτ αζ ομν κθζεε ωξ ψ ψηκκε δεεζρβψαπσρ κα νωξ.
To fornication are referred, 1. concubinage, which is the habitual commerce of an unmarried man with an unmarried woman; - 2. prostitution, which is the state of a woman prostituted to all.
The circumstance of concubinage or prostitution is not necessarily to be declared in confession, since per se it does not change the species of the sin. But per accidens it is often to be explained in order to manifest the state and kind of occasions, and always must be opened to the Confessor when he asks. - St. Lig., n. 432.